Do You Know Duplex Steel 2205?

The duplex steel 2205 is composed of 22% Cr, 2.5% mo and 4.5% Ni-C alloy. To some extent, it has features of austenitic and ferritic stainless steel. And the ideal organization is 50% with each other. We can combine the superior toughness of the austennitic stainless steel, high strength of weldable plain stainless steel and resistance to chloride stress corrosion through control the chemical composition and heat treatment process correctly.

It has good overall and local impact toughness and stress corrosion resistance. Its yield strength is more than twice that of an ordinary austenitic stainless steel. This feature allows designers to reduce weight when designing products, giving it a price advantage over 304 and 316 stainelss steel.

The 2205 duplex stainless steel is poor thermoplasticity, because the deformation behavior of austenite phase and ferrite phase are different during hot working. Because of the different softening process of the two phases, and inhomogeneous distributions of stress and strain are produced in the two phases, which leads to nucleation and propagation of the phase boundary crack.

1. Corrosion Resistance

Local Corrosion Resistance: The content of Cr, Mo and N make it has strong resistance to pitting corrosion and crevice corrosion in oxidizing and acidic solutions.

Uniform Corrosion: Anti-corrosion property of 2205 is better than 316L and 317L in most circumstances.

Stress Corrosion Resistance: The dual-phase microstructure of stainless steel is helpful to improve the stress corrosion resistance. Chloride stress corrosion cracking occurs in austenitic stainless steel in a certain temperature with stress tension, oxygen and chloride. Because these conditions are not easy to control, the use of 304L and 316L in this regard is limited.

Corrosion Fatigue: High strength of 2205 duplex stainless steel and its corrosion resistance that make it with high corrosion resistance fatigue strength. Machining equipment is susceptible to corrosion environment and loading cycle, and the feature of 2205 isperfectfor such applications.

2. Application Area

In the first, it is widely used in the field of pressure vessel, high pressure storage tank, high-pressure pipe and heat exchanger ( chemical processing industry). Second, That is a good choice about oil and gas pipeline and heat exchanger pipe fitting. We often see this material in parts with high strength and corrosion resistance. Thirdly, 2205 is very popular in the sewage system, storage processing system, pulp and paper industrial classifier and bleaching equipment. Last but not the least, it is the first choice of food processing equipment.